Лизоцим

Lysozyme (muramidase) hydrolyzes preferentially the beta-1,4 glucosidic linkages between N-acetylmuramic acid and N-acetylglucosamine which occur in the mucopeptide cell wall structure of certain microorganisms, such as Micrococcus lysodeikticus. A somewhat more limited activity is exhibited towards chitin oligomers. Lysozyme is of widespread distribution in animals and plants. That which has been most extensively studied is from hen egg white (lysozyme C). Lysozyme is also found in mammalian secretions and tissues, saliva, tears, milk, cervical mucus, leukocytes, kidneys, etc. Lysozyme is inhibited by surface-active reagents such as dodecyl sulfate, alcohols and fatty acids. Imidazole and indole derivatives are inhibitors via formation of change-transfer complexes. Useful for the rapid isolation of RNA from gram negative bacteria. Can be used to prepare small amounts of plasmid DNA.

Catalyzes the hydrolysis of peptidoglycans found in bacterial cell walls. Lysozyme catalyzes is utilized for the hydrolysis of peptidoglycans found in bacterial cell walls. It is used as a precursor in the production of spheroplasts. It is also used as a preservative against many food spoiling microorganisms. It is used in skin care in order to cure and prevent acne and bed sores, dental and oral conditions. It is used for lysing E. coli and Streptomycetes for extraction purposes such as extracting group specific antigen. Further, it is used in non-pasteurized beer.

Lysozyme from chicken egg white has been used for the extraction of genomic DNA from bacterial cells.It has been used as an external standard for MALDI-TOF (matrix assisted laser desorption ionization-time of flight) mass analysis.
Enzyme breaks down the cell walls of bacteria; used to prepare spheroplasts.

Lysozyme from chicken egg white, is a protein that can show broad spectrum of antibacterial activity against gram positive and gram negative bacteria. Its antimicrobial activity can be enhanced by pretreatment of the target microbial cells with chelating agents like ethylenediaminetetraacetic acid (EDTA).

Lysozyme hydrolyzes β(1→4) linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. Gram-positive cells are quite susceptible to this hydrolysis as their cell walls have a high proportion of peptidoglycan. Gram-negative bacteria are less susceptible due to the presence of an outer membrane and a lower proportion of peptidoglycan. However, these cells may be hydrolyzed in the presence of EDTA that chelates metal ions in the outer bacterial membrane.The enzyme is active over a broad pH range (6.0 to 9.0). At pH 6.2, maximal activity is observed over a wider range of ionic strengths (0.02 to 0.100 M) than at pH 9.2 (0.01 to 0.06 M).